The invention relates to stabilized gas-in-liquid dispersions or foams.
Pure liquids generally cannot foam unless a surfactant or other material that reduces surface tension is present in the liquid. The surfactant functions by lowering the surface tension of the liquid such that a gas bubble introduced below the surface of the liquid can be maintained in the liquid. The surfactants can also stabilize the foam after it is formed. Such surfactants include, e.g., ionic, nonionic, and polymeric surfactants.